Method and machine for producing double creped paper



Nov. 4, 1969 L. w. KREHNBRINK 3, ,6

7 METHOD AND MACHINE FOR PRODUCING DOUBLE CREPED PAPER.

Filed Jan. 21, 1966 6 Sheets-Sheet l INVENTOR Lewis W. Krehnbrink BY fl wm 9W M49312.

ATTORNEYS N V- 1969 1.. w. KREHNBRINK 3, 76, 4

METHOD AND MACHINE FOR PRODUCING DOUBLE CREPED PAPER Filed Jan. 21, 1966 6 SheetsSheet 2 INVENTOR Lewis W. Krehntbrink BY I yoywm kgg maZ e.

METHOD AND MACHINE FOR PRODUCING DOUBLE CREPE?) PAPER NO\ 4, 1969 w. KREHNBRINK 6 Sheets-Sheet 5 F'ilgd Jan. 21, 1966 coma u m m Q Q n" D Q (E c c A Q Q l. o c 3 u" a a Q m O o a 3 a w m 0 :u q Q a s -4 [F -w 5 m m 4 Fig. 4 I 75} kl'lll I I U IH IUHHHHH INVENTOR Lewis W. Krehnbrink ATT ORN EYS 1969 Y w. KREHNBRINK 3,475,644

METHOD AND MACHINE FOR PRODUCING DOUBLE CREPED PAPER I Filed Jan. 21, 1966 6 Sheets-Sheet 4 INVENTOR Lewis W. Krehnbrink ATTO R N EYS 1969 1.. w. KREHNBRINK METHOD AND MACHINE FOR PRODUCING DOUBLE CREPED PAPER 6 Sheets-Sheet 5 Filed Jan. 21, 1966 INVENVTOR Lewis W. Krehnbrink N 1969 L. w. KREHNBRINK 3,475,644

METHOD AND MACHINE FOR PRODUCING DOUBLE CREPED PAPER Filed Jan. 21, 1966 6 Sheets-Sheet 6 INVENTOR Lewis W. Krehnbrink ja /4 M 5 [ma/Z2.

United States Patent METHOD AND MACHINE FOR PRODUCING DOUBLE CREPED PAPER Lewis W. Krehnbrink, Cincinnati, Ohio, assignor to C11]- cinnati Industries, Inc., Cincinnati, Ohio, a corporation of Ohio Filed Jan. 21, 19 66, Ser. No. 522,138 Int. Cl. B31f 1/14; D21h 5/24 U.S. Cl. 162-111 18 Claims ABSTRACT OF THE DISCLOSURE This invention has to do with the manufacture of paper or other web characterized by crossing sets of creping crinkles which are diagonally disposed in the direction of the length of the webs. Webs of this character, which are universally stretchable, have hitherto been made in accordance with the teachings of a number of U .8. Letters Patent including: 2,008,181, Kemp; 2,008,182, Kemp; 2,071,347, Kemp; 2,399,256, Rowe; 2,567,967, Rowe; 2,610,935, Rowe.

In commercial operation, it has been the practice to adhere a web to be creped to the surface of a relatively large creping cylinder by means of a positive adhesive and a press roll or rolls. The web is removed from the cylinder and creped in the course of such removal by a creping knife which is substantially helically disposed about the surface of the cylinder. In leading the web away from the creping knife it has been turned back on itself so that it leaves the first creping cylinder more or less in the direction of the cylinder axis.

However, two basic factors will determine the exact angle of departure of the web. These factors are: the angle of the knife to the cylinder axis, and the amount of change in the width of the web-as it leaves the creping knife compared to its width as it approaches the knife. Factors that control this width relationship of the web, with a given knife angle, include: the nature of the adhesive used to adhere the web to the creping surface, the temperature of the adhesive, the amount of moisture in the web being creped, the amount of pressure applied by the press rolls, the creping V, and the kind of material being creped. It will be understood that the contraction of the web widthwise as well as lengthwise will result in a departure of the web from the line along which the crinkles are being formed in a direction other than parallel to the direction of motion of the web as it approaches the line of crinkle formation. This would be true even if the creped web were carried forwardly over the knife.

It is'more advantageous to turn the web back. upon itself as indicated above, since the web will be subjected to less strain as it goes from a helical line on a curved surface to a fiat plane. Where the web' is to be creped a second time on a separate creping cylinder, it must be delivered to that cylinder in a direction at right angles to the cylinder axis. It has been suggested that the second cylinder and its appurtenancescould be mounted in a movable and rotatable fashion so that it could be brought into a position to receive the single creped web in the direction in which it leaves the first creping cylinder,

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taking into account any removal of stretchability occurring during the transfer. This is not generally feasible because of cost factors and the inconvenience of moving and rotating a large piece of apparatus each time a change occurs in the widthwise stretchability of the web.

As a consequence, elaborate adjustable transfer mechanisms have been worked out for carrying a web creped on a first creping cylinder to a second creping cylinder located at right angles to the first. These transfer devices are inconvenient in use, and cause a loss of stretchability.

Moreover, it will be clear that the initially untreated web must approach the first cylinder at a right angle to the cylinder axis. As it leaves the first cylinder, the web travels in a direction more or less in line with the cylinder axis through the transfer apparatus until it is brought to the surface of the second creping cylinder in a direction at a right angle to the axis of the second cylinder. The single-creped paper is adhered to the second cylinder and is removed therefrom by a second helically disposed knife so as to make a second set of creping crinkles in the web crossing the first set of crinkles. In removing the web from the second cylinder, it is again turned back upon itself so as to leave the second cylinder in a direction more or less in alignment with the axis of the second cylinder. The same considerations apply here, so that the actual direction of departure from the second cylinder will vary with the factors noted above unless the web is forcibly pulled away in the direction of the second cylinder axis. Such a pulling operation, which changes the angle of departure of the web, results in an undesired differential removal of stretchability. Again, a transfer mechanism of some sort should be provided due to these variations. since subsequent steps have to be performed upon the web. In some instances, the web will be flattened and controlled as to its lengthwise and widthwise stretchability by the use of means for removing a portion of the longitudinal stretchability and by the subsequent action of a tenter, which has been found to be capable of reducing the widthwise stretchability to a specified value without essentially changing the longitudinal stretchability.

In any event, in prior art practices, the web has been led to the first creping cylinder in one direction, is caused to travel laterally between the first and second creping cylinders, and then to travel for subsequent treatment steps in a direction offset and parallel to its first path of travel. This is wasteful of factory floor space.

It has not hitherto been practicable to provide a straight-line operation, i.e., an operation in which the untreated web and the finished double creped web travel coaxially in the same direction. It is an object of this invention to provide means and a method in which coaxial travel is attained. p

In previous practices, it has been'impossible to avoid differential stretching of the web between the first and second creping cylinders and between the second creping cylinder and means for performing other steps on the web. This is because the creped web traveled from a helical line on a curved surface to a straight line on a flat surface. It is an object of this invention to provide a creping apparatus and a method of operation which avoids differential stretching.

In apparatus involving the use of substantially helically disposed creping knives, the knife structure and the means for backing it have been elaborate in nature. Also, if wide webs are to be creped, the cylinders have had to be very large in diameter. This has meant that any single piece of creping apparatus has been of large and heavy construction. It is an object of this invention to. eliminate the use of helical knives and. consequently such heavy and elaborate constructions. a

While it has hitherto been suggested that creping belts could be substituted for creping cylinders so as to permit fhe use of rectilinear as distinguished from helical knives, such suggestion has not obviated the difliculties first outlined herein. It is an object of this invention in one aspect to provide for the use of rectilinear knives and creping belts while avoiding these difiiculties.

It has also been hitherto understood that a web may be led to a creping cylinder and removed therefrom with a knife which is in alignment or substantial alignment with the axis of the cylinder. If the creping knife is caused to move in the direction of the cylinder axis during the creping operation, the web will tend to leave the cylinder in a direction other than at a right angle to the cylinder axis. Thus, the web becomes contracted both longitudinally and laterally; and the creping crinkles will become diagonally disposed, i.e., they will not lie at a right angle to the axis of the web (see US. Patent No. 2,494,334, issued Jan. 10, 1950 in the name of Dorst). This mode of operation again did not avoid the difiiculties set forth above. It is an object of this invention to provide a creping apparatus using traveling knives which are small, self-contained and capable of straightline operation.

It is an object of this invention to provide a creping apparatus in which one creping means is located above the other, with the elimination of adjustable transfer mechanism. This effects a great saving in the cost of the machine and in the factory floor space required.

In prior practice, where a double creped product was being made, it was necessary to provide translation means for the web, to accomplish a transfer of the web from a first creping machine to a second creping machine. The words translation means are used herein to denote means for causing a lateral shift in the direction of travel of the center line of the web. Such translation means, including rollers, bars and the like, tended to remove stretchability from the web despite various corrective measures which were employed. It is therefore an object of the invention to provide a mechanism making possible the direct transfer of the web from the knife of the first creping machine to the creping surface of the second creping machine without the necessity of intervening translation means. Thus, the creping knives not only determine the stretchability imparted to the web, but also may serve as the sole translating means determining the direction of motion of the web after the first and second creping treatments. It is an object of this invention to provide creping apparatus which can be incorporated into a paper making machine or located to receive the paper off the end of the paper making machine. In the first instance the creping apparatus of this invention may, for example, be located intermediate 2. series of drying cylinders so as to operate upon the paper web while it still contains some moisture, i.e., that moisture which will be removed by subsequent drying cylinders. In the second instance the creping apparatus will be operating upon otherwise finished and dried paper; but the location of the creping apparatus to receive the paper as it comes from the paper machine obviates the necessity of forming the paper into rolls, and handling, storing and moving the rolls prior to the creping operation.

These and other objects of the invention which will be set forth hereinafter or will be apparent to those skilled in the art upon reading these specifications, are accomplished by that apparatus and procedure of which certain exemplary embodiments will now be described. Reference is made to the accompanying drawings wherem: FIG. 1 is a perspective view of diagrammatic character showing one form of double creping apparatus comprising an upper belt creper, an adjustable lower belt creper and means for receiving the paper from the lower creping means.

FIG. 2 is a detailed elevational view with p rts broken away of one of the creping means showing mechanism for knife adjustment.

FIG. 3 is an end elevation of the same apparatus.

FIG. 4 is a top plan view thereof.

FIG. 5 is a detailed front elevation of a double creping apparatus of the present invention.

FIG. 6 is a detailed side elevation of the double creping apparatus of FIG. 5.

FIG. 7 is a partial side elevation of the double creping apparatus showing the upper creping machine (similar to that shown in FIG. 6) provided with an alternative means for causing the web to leave the knife in a horizontal plane.

FIG. 8 is a perspective view of diagrammatic character showing another embodiment of the invention.

FIG. 9 is a diagrammatic plan view of the embodiment of FIG. 8.

In the embodiments of FIGS. 1 to 7 inclusive, a first creping apparatus is provided utilizing an endless belt as distinct from a cylinder to provide the moving creping surface. The belt passes over sheaves or rollers at each end of an elongated horizontal portion of the machine frame, in such a way that the belt provides an upper flight and a lower flight moving in opposite directions. The paper or other web to be creped is led to the belt and pressed thereagainst preferably at the location of one of the end sheaves. It is not necessary that the web pass along the upper flight of the belt. Indeed it is preferable to lead the web around a pressure roller at the end of the upper flight of the belt so that the beginning portion of the upper flight is left free for the application of adhesive to the belt as later explained.

A creping knife extends across the lower flight of the creping belt at an angle to the direction of motion of the lower flight. The web is creped as the knife removes it from the lower flight of the belt. Means are provided to cause the web to leave the knife in a horizontal plane and to be redirected (without translation) downwardly to the creping surface of the second creping apparatus.

The web is pressed by a pressure roller upon the surface of a second creping belt which is essentially like the first creping belt. But since the knife by which the web was removed from the under side of the first creping belt was diagonally disposed (a term which will be used herein to indicate any positive and deliberate angularity of the creping knife to the direction of travel of the belt) the second creping belt will have to be oriented at a right angle to the center line of the paper, as it approaches the second creping belt. Consequently, the second creping belt is mounted upon a separate machine frame which is adjustable radially around the vertical axis of the machine. The second creping belt receives the single diagonally creped paper, and the difficulties heretofore inherent in effecting the transfer of a single diagonally creped web from a first creping cylinder to a second creping cylinder are completely avoided.

The single creped web is caused to adhere to the surface of the second creping belt and is removed from the surface of the lower flight thereof by another diagonally disposed creping knife in such a way as to produce a second set of creping crinkles crossing the first mentioned set.

Again, the web is caused to leave the knife of the second creping apparatus in a horizontal plane, this time by means of a conveyor which directs the Web out of the machine. Because of the opposite orientations of the creping knives with respect to the web being treated, the conveyor which is located below the second creping assembly may lie parallel to the first creping assembly. Thus the web being treated may enter and leavef the machine in the same direction, the rotary adjustment of the second creping assembly serving to take care of any changes in the angularity of the creping knives in cluding changes in the resident stretchabilities imparted to the web by the creping operations.

The apparatus, by comparison with structures heretofore employed for creping, is relatively simple and inexpensive, and occupies far less floor space than the machines hitherto provided for the formation of double diagonally creped papers. It may be noted also that the creping knives can be rectilinear in character as distinguished from the helical knife configurations which have heretofore been necessitated by the use of cylinders. At the same time, any adjustments required to control the direction of travel imparted to the web under treatment by the creping knives, are available to the operator of the machine. In the apparatus of the present inven tion, the angularity of the second creping machine and either the overall angularity of the knife or the creping V may be adjusted while the machine is operating to produce any desired condition of stretch in the final product and to insure that the final product is discharged from the apparatus on a center line parallel to and lying in the same vertical plane as the center line of the upper creping belt. In the prior art creping apparatus using a helical creping knife, neither the overall angularity of the knife nor the creping V could be adjusted without necessitating complete shut down of the creping apparatus and the provision of different backing means for the knife. In some instances the creping V could be adjusted by regrinding the knife itself, but all expedientshad to be employed on a trial and error basis, with intermediate shut down periods until the desired conditions were achieved.

In some instances it is desirable to have the double creped web discharge from the apparatus on a center line which is not parallel to the center line of the web to be creped. When this is the case, it is within the scope of the invention to make the conveyor adjustable about a vertical axis.

Referring more specifically to FIG. 1, the upper creping means comprises a metallic belt 1 of endless character mounted at its looped ends on rollers 2 and 3. These rollers are journaled in bearings in a machine frame (not shown). One at least of these rollers will be positively driven by motor means (not shown). It is, of course, essential that the belt be positively driven in such a way that no slippage will take place. This can be accomplished frictionally if desired, but preferably sprocket holes or notches are punched in the belt at intervals along one or both of its edges and sprocket wheels having teeth for engaging in the holes are made integral with or are affixed to the ends of the rollers.

The web to be creped, may be led to the. first creping apparatus in a condition already coated with creping adhesive and already containing a desired amount of moisture for. the creping, operation. Again, it is possible to coat the surfaces of the belt 1 with a creping adhesive and to lead the web against the adhesive coated surface of the belt. In FIG. 1 there is diagrammatically shown a coating roll 4 of a coating apparatus. The coating roll 4 contacts the surface of the belt 1 and coatsit with creping adhesive. The nature of the creping adhesive does not constitute a limitation on this invention. It will ordinarily be either a water dispersion of thermoplastic material, or a hot melt. The Websto be crepedmay be led to the apparatus in any suitable fashion. For purposes of an exemplary showing, a carrier roll 6 is shown above the first creping unit.

A resilient pressure roller 7 will be located in association with the belt 1. The pressure roller 7 is preferably located adjacent the belt roller 3 which may serve as a back-up means for the pressure roller, obviating the necessity of providing additional back-up means for it elsewhere in the path of travel of the belt 1. The pressure roller acts to press the web to be creped against the surface of the belt. It is preferred that the web 5 contact the belt 1 immediately ahead of the nip of the belt and the pres- '6 sure roller 7. This may be accomplished by the proper location of the carrier roll 6. If heat is required to activate the adhesive, the belt roller 3 may be heated electrically or otherwise.

With apparatus as compact as that which has been described, it is also possible to locate the entire creping machine within a. chamber, (not shown) in which an ambient temperature sufficient to insure the bond between the paper and the creping surface is maintained, or an atmopshere of sufficient relative humidity to contribute a desired amount of moisture to the web, or both.

As has been indicated, a diagonal creping knife will be applied to the under fiight 1a of the belt. This knife may takevarious forms. A particular form of knife and mounting will be outlined at length hereinafter. In FIG. 1 there has been diagrammatically illustrated a knife structure in the form of an elongated but relatively thin strip of metal 8 coming from a supply reel 9. The knife will be held in position by the knife supports (not shown) and maybe hacked so as to be heldagainst the creping surface In in any way desired. When one length of the knife structure has become so worn as to render its further use inadvisable, another length may be withdrawn from the supply reel 9.

Since for various purposes it may be desired to change the angularity of the creping knife 8 to the direction of motion of the belt 1, the support means for the knife (not shown) may be made adjustable.

As indicated in FIG. 1, the' diagonally creped web 5a passes over a redirector roller 10 which causes the web 5a, as the creping knife 8 removes it from the belt 1, to follow a horizontal path and then to pass downwardly to the second creping apparatus. It will be noted that the redirector roller 10 imparts no translation (as defined above) to the web 5a and thus has a minimal effect on the stretchability of it.

A second creping belt 11, passing over rollers 12 and 13 will be so oriented as to receive the single creped web 5a directly. The rollers 12 and 13 will be mounted in hearings in a second machine frame (not shown). The second machine frame may be supported directly upon circular or semi-circular tracks on the factory floor or it may be swiveled on the factory floor to provide adinstability of the second creping apparatus as described fully hereinafter.

The nature of and the appurtenances used in connection with the second creping belt 11 may be the same as those above described in connection with the first creping belt. The web will be removed from the under flight 11a of the second creping belt by an oppositely diagonally disposed creping knife diagrammatically indicated in FIG. 1 at 14. The second creping belt may be provided at one end with a coating roll 15 substantially as above described, and with a pressure roller 16 at the other end. Again, the web 5a preferably contacts the belt 11 just ahead of the nip of the belt and the pressure roller 16. This may be accomplished by proper location of the redirector roller 10.

A- conveyor (generally indicated at 17) will be provided in accordance with this invention. The nature of the-conveyor 17 will be more fully described hereinafter. The conveyor lies beneath the second creping apparatus andis adapted to receive the double creped web 51: directly therefrom and to transport it in a horizontal plane and in a direction which is preferably a continuation of the direction in which the untreated web was led to the machine.

It 'will be understood that the first creping belt 1 will be powered by driving one or both of its rollers 2 and 3, that the second creping belt 11 will be driven by powering one or both of its rollers 12 and 13, and that the conveyor 17 will also be powered. The power required by the creping belts will be substantial and must be suflicient to accomplish the work of creping the web by removing it from the belts as in ordinary creping operations using a positive adhesive. Since the conveyor 17 need only transport the paper after it has been released by the second creping knife, it may be relatively lightly powered. Powering means have not been illustrated in the figures since they may consist of electric motors mounted on the several machine frames and connected with the respective rollers by any suitable power transmission means each individually adjustable for the desired speed ratios with respect to the others. It will be noted that the conveyor 17 as illustrated extends in parallelism with the belt 1 of the first creping apparatus, and does not re quire angular adjustment as hereinafter more fully explained, unless it is specifically desired to remove the web b in a direction not parallel to the direction of the web 5.

In'FIGS. 2, 3 and 4, the details of part of the apparatus of FIG. 1 are shown with greater clarity. FIGS. 2, 3 and 4 have been simplified in that they show only the lower creping unit. It will be understood by the skilled worker in the art that the upper creping unit will be generally similar in construction.

The creping unit is shown as comprising an endless belt 25 with a lower flight 25a. The belt is mounted at its ends upon roller elements affixed to shafts 45 and 46. These shafts pass through side frame members 30 and 31. Sprockets 47 and 48 are also splined to the shafts; and the belt is shown as provided with spaced openings 49 adjacent either edge for engaging the sprocket teeth. The mode of mounting the side frame elements 30 and 31 will be described hereinafter.

Two upright elements 50 and 51 are located one to either side of the frame 30, 31. The upright elements are interconnected at the bottom by a base structure 52, and at the top by a bridge structure 53, forming a framework. The framework is pivoted by means of a shaft 54 having a vertical axis to a means indicated at 55 on a suitable sub-base or on the factory floor. The shaft 54 has splined to it a worm wheel 56 which in turn is engaged by a worm 57 on a shaft 58 mounted on independent supports 59. The shaft 58 is provided with a hand wheel 60, or a motor or other means (not shown) by which it may be rotated; and it will be evident that the entire framework 50 through 53 may be swung about the vertical axis of the shaft 54. This swinging motion may be accomplished without the necessary movement of the belt and its frame members 30, 31; and the purpose of the swinging of the frame 50 through 53 is to adjust the angularity both of a creping knife or doctor and of an opposed belt support of pressure sustaining element with respect to the direction of motion of the under flight 25a of the belt 25.

It will be understood that the side elements 50 and 51 of the frame are spaced apart sufficiently to permit a swinging motion of the frame 50 through 53 from a position in which the overall angularity of the knife to the direction of the motion of the belt 25 is less than, say, about 30 to greater angularities including 90, if straight creping is to be done. A similar range of knife setting angles will be provided for the knife of the upper creping machine.

In order to withstand the pressure of the creping knife against the outer surface of the lower flight 25a of the belt, an arbor element 62 extends across the machine. It will be understood that this element passes through elongated openings in the frame elements 30 and 31 to permit the desired swinging motion of the frame. Hydraulic cylinders 63 and 64 (or other pressure exerting means) are fastened to the bridge element 53. The pistons 65 and 66 of these elements engage in recesses near the ends of the arbor element.

The arbor element 62 is so shaped, as best shown in FIG. 4, as to support a pressure sustaining element 67 in a vertically adjustable position. The pressure sustaining element may have various constructions. It may, for example, be an elongated block of carbon, of reinforced thermosetting resin, or of metal having a low coefficient of friction with respect to the substance of the belt 25. With many such substances, a film of water may be used between the belt and the element 67. Preferably an inflatable tube of flexible material 68 is interposed between the arbor 62 and the element 67. Expansion of this tube by means of internal fluid pressure furnishes a means for accurate equalization of the pressure of the element 67 against the belt. The pressure sustaining element 67 may, itself, be made of flexible material and thus be capable of assuming a non-rectilinear conformation. This is also true of the knife 76 so that the knife will conform to the belt at all times.

Variations of this structure are possible; and the arbor 62 may, if desired, be provided with a rotatable pressuresustaining roll or with a series of closely spaced casters in lieu of the block 67. It will be understood by one skilled in the art that for purposes of clarity the arbor 62 and pressure-sustaining element 67 have been illustrated as being larger than they would normally have to be in practice.

A rockable knife support 69 is journaled with respect to the uprights 50 and 51. Preferably this knife support will also be journaled upon and held in position by a heavy beam-like member 70, also attached to the uprights 50 and 51.

The knife support 69' is provided at both ends with a gear segment 71, having teeth meshing with a worm 72 on a shaft 73, journaled in a bracket 74 on the upright 50. The shaft 73 may be turned by a hand wheel 75, or a prime mover. This will have the effect of rocking the knife support 69 for the purpose of changing the angularity of the creping V. The knife proper is preferably an elongated element 76, substantially rectangular in cross section and mounted in a slot 77 in the knife holder. This permits renewal of the knife as it becomes worn by a slow or rapid, continuous or intermittent endwise movement of the knife 76 in the slot 77 as required. Means for endwise movement of the knife is not shown.

It will be evident that the line of bearing of the knife 76 against the belt is at all times opposite and parallel to the line of support furnished by the element 67 or its equivalent, and this irrespective of the angularity of the frame 50 through 53 to the direction of motion of the belt. The structure described enables the operator to adjust the overall angularity of the knife to the direction of motion of the belt so as to form diagonal creping crinkles in the web at specific angularities to the web edges. This may be accomplished by adjusting the hand wheel 60. The angle of the creping V may be adjusted by the hand wheels so as to vary the fineness or coarseness of the creping crinkles. Pressure of the knife against the under flight of the belt may be adjusted by varying the fluid pressure in the conduit 68, or the fluid pressures in the cylinders 63 and 64, or both. While hydraulic cylinders are preferred, it is possible to employ instead screw means or other means for exerting pressure upon the ends of the arbor 62.

While it is true that the angle at which the creped paper will leave the creping knife of the first unit is dependent upon a number of factors such as the degree of contraction of the web during the first creping operation, the widthwise and lengthwise stretchabilities imparted to the web and the departure of the lines of he creping crinkles from exact parallelism with the creping knife, the second creping unit shown .in FIGS. 1 to 6 inclusive may be adjusted about its pivot (as described hereinafter) so as to receive the single-creped web in the direction of movement of the belt of the second creping unit. But the angle at which the double-creped web leaves the second creping unit can be adjusted by varying the angularity of the knife of the second creping unit. As a con sequence, the conveyor beneath the second creping unit may be located in a fixed position with respect to the first creping unit. This position may be but is not necessarily one of exact parallelism with the first creping unit.

In the modern manufacture of double-diagonally creped papers, the object is to produce the webs with an excess stretchability in both directions. The longitudinal stretchability of aweb may be diminished by stretching the web lengthwise. This involves some loss of widthwise stretchability; but it has been found possible to remove additional widthwise stretchability by the use of a tenter, without substantially affecting lengthwise stretchability. In this way it is possible to manufacture creped webs of accurately determined lengthwise and widthwise stretchabilities as specified by the customer in accordance with his needs. The stretching and tentering operations are accomplished after the web has left the conveyor 17 (see FIG. 1).

Thus no problem of transfer of the creped web from thefirst to the second creping units is involved in the use of the present invention. The apparatus of the present invention may be preset and started up in any desired manner. A preferred procedure includes the steps of first setting the second creping unit (with respect to the speed of the belt and angularity of the unit and knife setting) to deliver the desired product to the conveyor. The cc nditions of the first creping unit are then set to deliver the single creped web properly to the second creping unit. When the web has been threaded through the apparatus, and the apparatus is running, final adjustments may be made as described above. Thus, the apparatus can be adjusted to provide a straight line operation in which the web enters the creping machine in one direction and leaves it in the same direction, so that the creping machine can either be incorporated into a papermaking machine or used at the end of a paper-making machine.

An exemplary double-creping apparatus, in accordance with the teachings of this application, is illustrated in detail in FIGS. 5, 6, and 7. A first creping unit generally indicated at 78 is shown as mounted by means of suitable frame members (described more fully hereinafter) over a second creping unit generally indicated at 79. In order to have a clearer showing of the apparatus in FIGS. 5 and 6, the lower creping unit is shown oriented at a 90 angle with respect to the upper creping unit.

The lower creping unit is similar to that described with respect to FIGS. 2, 3 and 4, and like parts have been given like index numerals. In this embodiment, the side frame members 30 and 31 are supported at their ends by upright frame members 80 and 81 respectively. The uprights80 and 81 are affixed to a horizontal support 82. It will further be noted that the base member 55 to which the frame 50 through 53 is pivotally aflixed, also rests on the horizontal support 82,-The same is true of the supports 59 forthe shaft 58.

The horizontalsupport 82, upon which the entire lower creping unit rests, is itself pivoted by means of a shaft 83 having a vertical axis to a means indicated at 84 on a factory floor or suitable sub-base 85. The shaft 83 has splined to it a worm wheel 86 which in turn is engaged by a worm 87 on a shaft 88 mounted on independent supports 89. The shaft 88 may be provided with a hand wheel 90, or a motor or other means (not shown) by which it may be rotated; and it will be evident that the entire lower creping unit 79 may be swung about the vertical axis of the shaft 83 to adjust the angularity of the lower creping unit with respect to the upper creping unit.

The lower creping unit may be provided with a coating apparatus for coating the belt 25 with a creping adhesive. For purposes of clarity, the coating apparatus is shown in FIG. 6 only. The coating apparatus comprises a pan 91, a pick-up roll 92, a transfer roll 93 and a coating roll 94. The pan, pick-up and transfer rolls are supported on a bracket 95 on a pair of uprights 80 and 81. The coating roll 94 which applies the adhesive to the belt 25, has its ends journaled in supports (one of which is shown at 96) on the same pair of uprights 80 and 81.

The lower creping unit may also be provided with a resilient press roll 97 (for clarity shown only in FIG. 6) having its ends journaled in suitable supports (one of which is shown at 98) affixed to the opposite pair of uprights and 81. The press roll 97 serves to press the web to be creped against the surface of the belt 25.

The upper creping unit 78 is substantially the same as the lower creping unit and like parts have been given like index numerals in each instance followed by a.

The upper creping unit comprises a creping belt 25a having a lower flight 25aa passing over rolls and sprockets 47a and 48a journaled in the ends of side frame members 30a and 31a. The upper creping unit is supported by a framework comprising pairs of upright members 99 and 100 surmounted by a horizontal frame member 101. The ends of the side frame member 30a are affixed to the upright members 99, while the ends of the side frame member 31a are afiixed to the frame members 100.

While eliminated from FIG. 6 for purposes of clarity, coating apparatus and a press roll are shown in FIG. 5. The coating apparatus is the same as that shown with respect to the lower creping unit and comprises a bracket 95a supporting a creping adhesive pan 91a and pick-up and transfer rolls 92a and 93a respectively. A coating roll 94a has its ends journaled in support means (one of which is shown at 96a) affixed to an adjacent pair of upright frame members 99 and 100. A resilient press roll 97a coacts with the belt 25a at the other end of the upper creping unit and has its ends journaled in support means (one of which is shown at 9811) affixed to the other pair of upright supports 99 and 100.

The frame member 50a through 53a is substantially the same as the frame member 50 through 53 of the lower creping unit, and supports a blade 79a with its support and adjustment means as well as the pressure sustaining element 67a together with its appurtenances. These elements have been described in detail with respect to FIGS. 2, 3 and 4.

Unlike the frame member 50 through 53 of the lower creping unit, the frame member 50a through 53a of the upper creping unit is pivotally suspended from the bridge of the main frame member. A shaft 102, having a vertical axis, is aflixed to the frame member 53a and passes through the member 101 and a support means 103 afi-lxed to the member 101. The upper end of the shaft 102 has a worm wheel 104 splined to it, which in turn is engaged by a worm 105 on a shaft 106 mounted on independent supports 107 affixed to the horizontal frame member 101. The shaft 106 may be provided with a hand wheel 108, or a motor or other means (not shown) by which it may be rotated; and it will be evident that the entire framework 50a through 53a may be swung about the vertical axis of the shaft 102.

The embodiment of FIGS. 5 and 6 is provided with means equivalent to the redirector roller 10 described in connection with FIG. 1. This means is located between the upper and lower creping units, and for purposes of I clarity is shown only in FIG. 6. As indicated above, the

redirector means between the upper and lower creping units is provided for the purpose of causing the single creped web to leave the first creping knife in a horizontal path of travel, and thereafter to redirect the web downwardly to the creping surface of the second creping apparatus.

The embodiment of the redirector means illustrated in FIG. 6 comprises a continuous belt 109 passing over rollers 110 and 111. The roller 110 is journaled in suitable support means located on an adjacent pair of uprights 80 and 81. One of these support means is illustrated at 112. The roller 111 is journaled in suitable support means located on the other adjacent pair of uprights 80 and 81. One of these support means is illustrated at 113. It will be noted that the roller 111 is lower than the roller 110 so that the continuous belt 109 slants upwardly in the direction of travel of the web. Either or both of the rollers 110 and 111 will be driven by motor means (not shown) 1 l in such a way that the speed of the belt 109 may be independently controlled.

As indicated in FIG. 6, when a web is initially threaded through the upper creping unit, the single creped web (shown in broken lines at 114) will fall downwardly onto the upper flight of the belt 109 and the end of the web will be carried over the roller 110 and will fall downwardly toward the creping belt 25 of the lower creping unit 79. When the web is properly threaded through the lower creping unit 79, it will assume a position shown in solid lines at 115. In its proper position, it will be noted that the web 115 leaves the first creping knife in a horizontal path of travel, and passes over the roller 110. Having passed the roller 110, the web 115 travels downwardly and contacts the creping belt 25 of the lower creping unit 79 just ahead of the nip between the belt 25 and the pressure roller 97.

It is important that the web leave the first creping knife in an initial path of travel which is horizontal. This avoids a twisting and a distortion of the web which would remove some of its stretchability. Furthermore, it will be noted that when the web is in its proper position, it will contact only that portion of the belt 109 which is passing over the roller 110, and the roller 110 serves to cause the web to properly approach the lower creping unit. The roller 110 does not cause a translation of the web (as that term is defined above).

Any stretch removal in the web during its passage from the upper creping unit 78 to the lower creping unit 79 may be controlled by the speed of the belt 109. The speed of the belt 109 will depend upon the speed of the belt 25 of the lower creping unit, and will preferably be slightly less. In this way, the proper path of travel of the web between the belt 109 and the creping belt 25 of the lower creping unit will be maintained.

FIG. 7 is a fragmentary view of the structure of FIG. 6, showing the first creping unit 78 and another embodiment of the redirector means. In FIG. 7, like parts have been given like index numerals. In this embodiment, the redirector means comprises a redirector roller 116, the ends of which are shown at 117. The spaced pair of tracks are affixed to adjacent pairs of uprights 80 and 81, and are inclined upwardly in the direction of the path of travel of the web. Means (not shown) are provided to cause the redirector roller 116 to move from an inactive position shown in dotted lines, in the direction of the arrow A, to a final position shown in solid lines.

With this embodiment, as the web is threaded through the upper creping unit 78, the single creped portion of the web (shown in broken lines at 114) will leave the first creping knife and fall directly downwardly. At this point, the redirector roller 116 will begin its movement along the rails 117. The redirector roller 116 will contact the fallen web 114 and will carry it to that position wherein the roller 116 is illustrated in solid lines. When the single creped web is properly threaded through the lower creping unit 79, it will assume a path of travel indicated in solid lines at 119.

Thus the final position of the single creped web indicated at 119 in FIG. 7 is the equivalent of the final position of the web indicated at 115 in FIG. 6. Again, the path of travel of the web between the first creping knife and the roller 116 is horizontal, and the roller 116 redirects the web (without translation) downwardly to a proper approach to the creping surface of the lower creping unit. In this instance the roller 116 may be an idler roller or it may be driven to control the stretch removal as described with respect to the belt 109 of FIG. 6.

A conveyor is provided for the double creped paper leaving the lower creping unit. For purposes of clarity, the conveyor (indicated diagrammatically at 17 in FIG. 1) is illustrated in detail only in FIG. 5. In the embodiment shown in FIG. 5, the conveyor comprises a continuous belt 120 passing over rollers 121, 122 and 123. The roller 121 is journaled in suitable support means (one of which is shown at 124) affixed to an adjacent pair of uprights 99 and 100. The rollers 122 and 123 are respectively journaled in suitable support means (one each of which is shown at 125 and 126) aflixed to the other adjacent pair of uprights 99 and 100. It will be noted that the upper flight of the belt 120 slants upwardly in the direction of the path of travel of the web and that portion of the belt 120 which passes over the roller 123 lies substantially in the same plane as the creping knife of the lower creping unit 79.

Both the upper and lower flights of the belt 120 pass through the frame member 50 through 53 of the lower creping unit between the elements 52 and 70. It will be understood by one skilled in the art that the position of the conveyor is slightly distorted in FIG. 5 since the lower creping unit 79 is illustrated as positioned at right angles to the upper creping unit for purposes of clarity.

The conveyor belt 120 will be driven independently, as described above, by suitable means (not shown). During the initial thread-up of the lower creping machine the double creped web (indicated in broken lines at 127) falls downwardly onto the upper flight of the belt 120. The end of the double creped web is carried by the belt 120 over the roller 123 to whatever further stage of operation is desired. After thread-up, and when the machine is running normally, the double creped web from the lower creping unit will assume the position shown in solid lines at 128. In this position the roller 123 insures that the web leaves the creping knife of the lower creping unit in a horizontal plane. Again, the roller 123 does not cause a translation of the web.

It is within the scope of the present invention to provide a conveyor comprising a single traveling roller in every way equivalent to the traveling redirector roller 116 described in FIG. 7. In this case the single roller when inactive would be located in a position substantially equivalent to the position of roller 121 in FIG. 5. In its fully activated condition the roller would assume a position equivalent to roller 123 in FIG. 5. The pick-up of the loose web during the threading operation and the maintaining of the web in a horizontal plane when the machine is running properly, would be the same as described above in connection with the roller redirector 116 in FIG. 7.

From the description of the embodiment of FIGS. 5 and 6 it will be noted that the upper creping unit 78 and the conveyor belt 120 are both supported by the upright frame members 99 and 100. The lower creping unit is not supported by the frame members 99 and 100, but rather is supported by means affixed to the sub-base or floor 85. Thus, the lower creping unit may be angularly adjusted in a horizontal plane independently of the upper creping unit and the conveyor. Furthermore, the creping blade of each creping unit may be independently angularly adjusted with respect to its creping belt. It will be understood by one skilled in the art that in FIGS. 5 and 6 power means for driving the belts of the upper and lower creping units as well as the belt of the conveyor have not been illustrated. These power means may be conventional as described above.

A straight line operation is also illustrated in FIGS. 8 and 9 in which creping drums are used instead of creping belts, generally in accordance with the teachings of the Dorst U.S. Letters Patent No. 2,494,334. Referring to these figures, a first creping instrumentality comprises a drum 127 which is mounted for powered rotation on a shaft having bearings (not shown). An endless knife 128 is carried by sheaves 129 and 130 at the ends of the cylinder so that the general plane of the endless knife passes through the axis of the cylinder. The upper portion of the knife is out of contact with the surface of the cylinder; but the lower portion 128a is in contact with the cylinder surface. It will be understood that the portion 128a of the knife will be tilted with respect to the creping surface so as to provide a desired creping V. The tilting of the knife as well as the fixing of the knife in an axial position on the cylinder surface is accomplished by the use of backing means (not shown).

A web of paper 131 may be laid on the surface of the cylinder 127 and adhered thereto by any of the substances hitherto employed in creping by means of positive adhesives, the adhesive substance being applied to the web or to the cylinder or both. A press roll is indicated at 132 and preferably the web will contact the cylinder 127 immediately ahead of the nip of the cylinder and press roll 132. The web is removed from the surface of the cylinder and concurrently creped by the portion 128a of the endless knife. As set forth in the Dorst patent, if during the creping operation the knife 128 is continuously moved in an axial direction, the web will tend to leave the cylinder 127 in a direction at an angle to its direction of motion on the cylinder surface, as shown at 131a. By consequence, the creping crinkles formed in the web portion 131a will lie aslant to the edges of the web.

The single diagonally creped web 131w is shown as passing over a roll 133 and returning to the surface of a second cylinder 134. The roll 133 may be so mounted as to lie parallel to the second creping drum 134, and may be fastened to the supporting framework for the second creping cylinder. The roll 133 acts as a redirector, maintaining the web in a horizontal plane as it leaves the creping knife 128 and redirecting the web to the second creping drum 131 without translation.

The second creping cylinder will be suitably mounted for powered rotation as above described in connection with the cylinder 127; and it will be provided with an endless band knife 135 passing over sheaves 136 and 137, one or both of which will be powered. The web 131a is shown as passing around a roller 138. It will be adhered to the surface of the second creping cylinder by a suitable adhesive carried by or imposed upon the web or upon the cylinder 134 or both. A press roll is indicated at 139 and the roller 138 may be so positioned as to cause the web to contact the cylinder 134 just ahead of the nip of the cylinder and the press roll 139. The web will be removed from the surface of the cylinder 123 by the lower flight 135a of the endless knife acting as a creping doctor as above described. By driving the knife 135 in the proper direction, a second series of creping crinkles may be formed in web portion 131b crossing the first set of creping crinkles in the Web portion 131a. The double creped web removed as indicated may, if desired, be carried by a conveyor similar to that described in connection with FIGS. 1 and 5.

The angularity of the diagonal creping crinkles to the edges of the treated web will depend upon the ratio of the speed of the web while in contact with a creping cylinder or drum to the longitudinal speed of the endless knife which removes the web from that cylinder. But transfer problems are solved without translation in the structure of FIGS. 8 and 9 by mounting the creping instrumentalities one above the other as shown, and by providing for a rotative adjustment of the second creping cylinder or drum about an axis indicated at 140. Thus the. second creping cylinder and the roll 133 may be adjusted to receive the single creped paper from the drum 127.

The apparatus of FIGS. 8 and 9 is capable of the same type of adjustments as described in connection with the embodiment of FIGS. 1 through 7. For example, adjustments may be made in the overall angularity and the creping V of each of the knives 128 and 135. Similarly, the angularity of the drum 134 with respect to the drum 127 may also be adjusted. Thus, the apparatus of FIGS. 8 and 9 may be so set as to cause the direction of motion of the web portion 131!) to be the same as that of web portion 131.

Modifications may be made in the invention without departing from the spirit of it.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An apparatus for successively imparting two sets of creping crinkles in a moving web, said sets of crinkles being non-parallel with respect to each other and the centerline of said web, said apparatus comprising a first creping assembly having a first moving creping surface and a first creping knife applied to said first surface, a second creping assembly having a second moving creping surface and a second creping knife applied to said second surface, means for supporting said creping assemblies one above the other and means for pivoting said second creping assembly about a vertical axis to locate the centerline of the second creping surface substantially parallel to the centerline of the web as it leaves said first creping knife.

2. The structure claimed in claim l including redirector means located between said first and second creping assemblies, said redirector means operating to direct said web from said first creping knife in a plane substantially parallel to that portion of said first creping surface to which said first creping knife is applied and to redirect said web onto said second creping surface, said redirector means being so oriented that the centerline of the web as it approaches the redirector means and the centerline of the web'as it leaves the redirector means lies in the same plane.

3. The structure claimed in claim 1 wherein a portion at least of said first creping knife is rectilinear and extends across said first creping surface, said portion of said first creping knife lying at a first angle to the centerline of said first 'creping surface, a portion at least of said second creping knife being rectilinear and extending across said second creping surface, said portion of said second creping knife lying at a second angle to the centerline of said second creping surface, and means for adjusting at least one of said first and second angles.

4. The structure claimed in claim 1 including means for adjusting the creping V of at least one of said first and second creping knives.

5. The structure claimed in claim 1 including support means for said web leaving said second creping knife, said support means being so oriented as to support said web with its centerline parallel to and lying in substantially the same vertical plane as the centerline of said first creping surface.

6. The structure claimed in claim 1 including a first frame, said first creping assembly being mounted on said first frame adjacent the top portion of said first frame, a second frame shorter in height than said first frame and located at least partially within said first frame, said second creping assembly being mounted on said second frame, and means for rotating said second frame about said vertical axis.

7. The structure claimed in claim 6 wherein each of said creping surfaces comprises a belt having upper and lower flights, means for applying said first creping knife to the lower flight of said first creping surface at an angle to the centerline of said last mentioned flight, means for applying said second creping knife to the lower flight of said second creping surface at an angle to the centerline of the said last mentioned flight, means for adjusting said angularities of the said first and second knives to the centerlines of said lower flights of the first and second creping assemblies, respectively, and means respectively in said first and second creping assemblies and lying above the lower flights of the belts thereof for providing resistance to the deflection of the said belts by the said knives.

8. The structure claimed in claim '6 including a web support means beneath said second creping assembly for supporting said web after it leaves said creping knife of said second assembly, said support means being so oriented as to support said web with the centerline of said web being parallel to and lying in substantially the same ver tical plane as the centerline of said creping surface of said first creping assembly.

9. The structure claimed in claim 7 wherein said first creping knife is mounted in a third frame, said second creping knife being mounted in a fourth frame, means for adjusting the position of said third frame with respect to said first frame about an axis perpendicular to the lower flight of said first creping surface and means for adjusting the position of said fourth frame with respect to said second frame about an axis perpendicular to the lower flight of said second creping surface to adjust the angularities of said first and second creping knives with respect to the centerlines of said first and second creping surfaces respectively.

10. A creping assembly for imparting a single set of creping crinkles in a moving web, said assembly comprising a creping surface and a creping knife, said creping surface comprising an endless belt having upper and lower flights, a portion at least of said knife being rectilinear, and means for supporting said portion of said knife across one of said flights and applying said portion of said knife to the outside surface of said last mentioned flight, backup means located adjacent the inside surface of said last mentioned flight to provide resistance to the deflection thereof by said knife and means for adjusting the position of said knife support means about an axis perpendicular to said last mentioned flight to adjust the angularity of said portion of said knife to the centerline of said creping surface prior to and during the creping operation.

11. The structure claimed in claim 10 including means for pivoting said portion of said knife about its long axis to adjust the creping V of said knife prior to and during the creping operation.

12. A self-threading apparatus for successively imparting two sets of creping crinkles in a moving web, said sets of crinkles being non-parallel with respect to each other and the centerline of said web, said apparatus comprising a first creping assembly having a first moving creping surface in the form of a belt with upper and lower flights, a first creping knife and means for applying said first creping knife to said lower flight of said first creping surface, a second creping assembly having a second moving creping surface in the form of a belt with upper and lower flights, a second creping knife and means for applying said second creping knife to said second creping surface, means for supporting said first creping assembly above said second creping assembly so that said web after it leaves said first creping knife may move downwardly onto said second creping surface, and means for pivoting said second creping assembly about a vertical axis to locate the centerline of the second creping surface substantially parallel to the centerline of the web as it leaves said first creping knife.

13. The structure claimed in claim 12 including means for applying said second creping knife to said lower flight of said second creping surface and support means for contacting said web after it leaves said second creping knife during thread-up and directing said web away from said second knife in a plane substantially parallel to said lower flight of said second creping surface.

14. The structure claimed in claim 12 including a redirector means to contact said web after it leaves said first creping knife during thread-up of said apparatus, to direct said web from said first creping knife in a plane substantially parallel to said lower flight of said first creping surface and to redirect said web onto said second creping surface, said redirector means maintaining said web in said directed and redirected condition during the creping operation with the centerline of said web in said directed and redirected condition lying in substantially the same vertical plane, said redirector means comprising an endless belt and means for varying the speed of said redirector belt independently of the speed of said first and second creping surfaces.

15. The structure claimed in claim 12 including a redirector means to contact said web after it leaves said first creping knife during thread-up of said apparatus, to direct said web from said first creping knife in a plane substantially parallel to said lower flight of said first creping surface and to redirect said web Onto said second creping surface, said redirector means maintaining said web in said directed and redirected condition during the creping operation with the centerline of said Web in said directed and redirected condition lying in substantially the same vertical plane, said redirector means comprising a roller, said roller being movable from a position out of contact with said web when said creping apparatus is shut down to a,position in contact with said web when said creping apparatus is operating, and means for imparting rotation to said roller.

16. A process of imparting a first and second set of creping crinkles to a moving web, said sets of crinkles being non-parallel with respect to each other and the centerline of the web, said process comprising the steps of creping said web on a first creping assembly comprising a first creping surface and a first creping knife applied to said first creping surface to produce in said web said first set of creping crinkles, creping said web on a second creping assembly comprising a second creping surface and a second creping knife applied to said second creping surface to produce in said web said second set of creping crinkles, and pivotally moving said second creping assembly about a vertical axis to locate the centerline of the second creping surface substantially parallel to the centerline of the web as it leaves said first creping knife.

17. The process claimed in claim 16 including the steps of directing said web away from said first creping knife in a plane parallel to that portion of said first creping surface to which said first creping knife is applied, redirecting said web from said last mentioned plane to said second creping surface while maintaining the centerline of said directed and redirected web in substantially the same plane, and directing said web away from said second creping knife in a plane parallel to that portion of said second creping surface to which said second creping knife is applied.

18. The process claimed in claim 16 wherein said first and second creping surfaces comprise first and second rotating cylinders respectively and said first and second creping knives comprise endless belt-like means and including the steps of orienting said first knife parallel to the axis of said first cylinder, orienting said second knife parallel to the axis of said second cylinder and moving said knives longitudinally across their repective creping surfaces during the creping operation.

References Cited UNITED STATES PATENTS 2,071,347 2/1937 Kemp 161-129 X 2,399,256 4/1946 Rowe 264--283 X 2,494,334 1/1950 Dorst 162-111 X S. LEON BASHORE, Primary Examiner U.S. Cl. X.R. 

